Ski boot binding heelpiece with movable body

ABSTRACT

Ski boot safety binding heelpiece able to occupy at least two positions, an open position and a closed position, in which latter it is suitable for the safe clamping of a ski boot for skiing purposes, the heelpiece comprising a movable body comprising a release spring to allow release of the boot by the opening of the heelpiece in the event of a force greater than a predetermined threshold, this body occupying two different positions in each of the two positions of the heelpiece, the body being movable relative to a carrier ( 1 ) about a connecting pivot, and the carrier ( 1 ) comprising a carrier base ( 3 ) and a release body comprising a release surface, in which the release surface is connected to the carrier base ( 3 ) by a first connecting means formed by the release body ( 4 ) and by a second connecting means formed by the connecting pivot connecting the carrier ( 1 ) to the movable body and at least one reinforcing arm ( 11 ).

BACKGROUND OF THE INVENTION

The invention relates to a heelpiece for a “movable body” type safetybinding device for a ski boot, that is to say, a device designed to keepthe rear of a boot securely on a ski by exerting pressure on the heel ofthe boot while pressing the whole boot forwards against a front bindingdevice, and ensuring automatic release of the rear of the boot if theskier falls forwards. It also relates to a binding device comprising afront binding device and a heelpiece of this kind, as well as to a skion which such a heelpiece is mounted.

DESCRIPTION OF THE PRIOR ART

A first family of heelpieces, described as “fixed-body heelpieces”,relies on a fixed body comprising the heelpiece release mechanism and ona very simple separate component which is rotatable relative to thisbody, of lever type, comprising at its front end a jaw for gripping theheel of a boot. Rotating this “jaw lever” relative to the fixed bodyenables the heelpiece to occupy two positions, one closed and one open,for locking or releasing a ski boot.

The present invention relates to a second family of heelpieces, referredto as “movable-body heelpieces”, which relies on a movable body able tooccupy a closed position and an open position, comprising at its frontend a jaw for gripping the heel of a boot in the closed position and inits rear part a mechanism for implementing the release function whichreleases the rear of the boot if a large force occurs, as when the skierfalls forwards. This body is usually rotatable about a carrier attachedto the ski, and can occupy the closed position for skiing and the openposition in which the skier can remove his or her boot.

One example of a heelpiece belonging to this second family of patents isdescribed in document FR2507095. This solution however has thedisadvantage of having a central body on which the very large movablebody pivots. This creates difficulties in adjusting the pivoting of thismovable body and limits the amplitude of its rotation, as it cannotreach a high enough position in the open position to make it easy toremove the boot and cannot reach a low enough position in the closedposition to exert a satisfactory forward force on the boot, resulting inpoor release during a twisting fall and requiring precise longitudinalpositioning of the adjustment to the length of the boot. Additionally, acentral body of this kind must be in metal in order to withstand thehigh forces which can occur in an application with a high releasethreshold, such as in the case of competition.

Consequently, the preceding approach has been abandoned in favor ofother heelpieces of a different design belonging to this second family.Examples are described in patents EP1745827, FR2765115 and EP0893146.These texts describe a tubular cylindrical body comprising at one end aheel clamp and a cam shaft supporting a cam formed in a cylindrical partconnected to two lateral arms of the carrier forming a U-shaped stirrup.The cam shaft represents the axis of rotation of the tubular cylindricalbody and forms a cam suspended between two lateral arms. This tubularbody provides the release function and usually comprises a helicalspring working in compression between a piston which presses against thecam and a stop situated towards the end furthest from the cam. The shapeof the cam is such that under spring pressure the boot, once fitted, ispressed forwards against the front binding and downwards against theski. Only a large force will pivot the body about the cam by pushing thepiston back and compressing the spring, thereby causing the heelpiece toopen. These heelpieces, which are more expensive and more effective thanthose of the first or “fixed body” family, rely on a single bodycombining all the essential binding functions and have releasemechanisms which release a boot under very high forces, which isparticularly appropriate for competition skiing. However, one drawbackwith these heelpieces is their great complexity. In particular, the camwhich is used is subjected to very high forces due to its positionbetween no more than two lateral bearing points and has to be made ofmetal in order to withstand these forces. Also, this cam usually has ashape with a flat part, which means that stability can only be achievedin the closed position of the heelpiece and not in its open position,which creates difficulties when putting the boot into and out of theheelpiece.

It is an object of the present invention to provide a simpler and lessexpensive movable-body heelpiece.

The invention achieves this object by providing an overall heelpiecestructure that offers good resistance to the cam forces, is suited to awide range of operation up to high release thresholds, and allows easyinsertion and removal of the boot and satisfactory forward pressure onthe boot.

SUMMARY OF THE INVENTION

More specifically, the invention relies on a ski boot safety bindingheelpiece able to occupy at least two positions, an open position and aclosed position, in which latter it is suitable for the safe clamping ofa ski boot for skiing purposes, the heelpiece comprising a movable bodycomprising a release spring to allow release of the boot by the openingof the heelpiece in the event of a force greater than a predeterminedthreshold, this body occupying two different positions in each of thetwo positions of the heelpiece, the body being movable relative to acarrier about a connecting pivot, and the carrier comprising a carrierbase or foot and a release body comprising a release surface, in whichthe release surface is connected to the carrier base by a firstconnecting means formed by the release body and by a second connectingmeans formed by the connecting pivot connecting the carrier to themovable body and at least one reinforcing arm.

The release body can thus be connected to the connecting pivotconnecting the carrier to the movable body and the release surface mayact on a piston of the movable body.

At least that part of the release body which comprises the releasesurface may be made of plastic or of fiber-reinforced plastic.

The release body may be a one-piece body made of plastic orfiber-reinforced plastic.

The movable body may have a downwardly open region between the jaw ofits forward end and a piston acted upon by the release surface of thecarrier.

The release body may be a central body extending from the carrier baseto the upper part of the carrier.

Additionally, the safety binding heelpiece may comprise two lateral armsarranged on either side of the release body. These lateral arms maydefine a space between the release body and themselves in such a way asto be able to accommodate a part of the movable body.

The release body may comprise an essentially cylindrical upper partoriented transversely relative to the heelpiece, comprising a transversetubular opening designed to accommodate the pivot connecting it to themovable body, this upper part comprising the release surface.

The release body may comprise a lower part connecting its upper part tothe carrier base, this lower part comprising a narrow part whosedimension measured in the longitudinal direction is between 8 and 14millimeters.

The movable body may have an amplitude of rotation of more than 70°between its two positions.

The release body and the arm or arms may comprise openings toaccommodate the pivot connecting them to the movable body.

In one advantageous embodiment, the release surface may be a ramp.

The invention also relates to a device for binding a ski boot to a ski,comprising a front binding to accommodate the front part of a ski boot,and a heelpiece as described above to accommodate the rear part of theski boot.

Finally, the invention also relates to a ski comprising a ski bootsafety binding heelpiece as described above.

DESCRIPTION OF THE DRAWINGS

These objects, features and advantages of the present invention will beexplained in detail in the following description of one particularembodiment offered without implying any limitation with reference to theattached figures, in which:

FIG. 1 is a perspective view of a heelpiece having a movable body in theclosed position according to one embodiment of the invention;

FIG. 2 is a perspective view of a heelpiece having a movable body in theopen position according to the embodiment of the invention;

FIG. 3 is a cross section on a longitudinal central plane through theheelpiece in the closed position according to the embodiment of theinvention;

FIG. 4 is a cross section on a longitudinal central plane through theheelpiece in the open position according to the embodiment of theinvention;

FIG. 5 is a perspective side view of the central body of the carrier ofthe heelpiece having a movable body according to the embodiment of theinvention;

FIG. 6 is a perspective side view of the carrier of the heelpiece havinga movable body according to the embodiment of the invention;

FIG. 7 is a rear perspective view of the carrier of the heelpiece havinga movable body according to the embodiment of the invention;

FIG. 8 is a rear view of the carrier of the heelpiece having a movablebody according to the embodiment of the invention; and

FIG. 9 is a bottom perspective view of the movable body of the heelpieceaccording to the embodiment of the invention.

To facilitate an understanding of the rest of the description, thelongitudinal direction x is here defined as the horizontal directionextending from the rear to the front of the heelpiece, the transversedirection y and the horizontal direction perpendicular to the directionx, and the vertical direction z, directed upwards, as perpendicular tothe horizontal plane defined by the axes x and y.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The heelpiece according to the embodiment of the invention comprises atubular body 21 which is movable about a carrier 1 designed forattachment to a ski by means of rails 2 formed on the lateral parts ofthe lower base or base 3 of the carrier to enable its longitudinalposition to be adjusted on a ski to adapt it to different sizes ofboots. The movable tubular body 21 comprises at its forward end a jaw or“heel clamp” 22 designed to grip the standardized rear lip of a skiboot.

The movable body 21 which can be seen more particularly in FIGS. 3, 4and 9, comprises within itself a release mechanism which allows theheelpiece to move automatically from the closed configuration forskiing, shown in FIG. 1, to the open configuration shown in FIG. 2, inwhich the ski boot can escape from the heelpiece. This release happensautomatically if the skier falls and produces a force on the jaw greaterthan a predefined threshold. The movable body 21 moves from the closedconfiguration to the open configuration by a rotational movementrelative to the carrier 1, about a pivot 10. To implement the releasefunction, the movable body comprises various components in its internalvolume, including a compression spring 23 pressing against the stop 25at the rear top end of the body 21 and against a piston 24 at its otherend. This piston 24 is acted upon by a release surface formed on thecarrier 1, detailed below. The release threshold can be modified in aknown manner by modifying the degree of compression of the spring 23using an adjustment screw 26 at the rear end of the movable body 21 formoving the stop 25. In this solution, the movable body 21 thus has thefeature of presenting a large downwardly open region 29 between its jaw22 and the release piston 24. This region is intended to accommodate therelease surface of the carrier, as will be detailed later.

The concept of the invention consists in reinforcing the release surfaceor cam which supports the forces of the movable body by connecting it bytwo complementary connecting means to the base of the carrier, includingat least one reinforcing arm and the body which carries the cam. Thismeans that the principal structure of the release surface which receivesthe greatest forces can be made of plastic, within a fixed body 4, whichwill be referred to here as the “fixed release body” 4. The fixedrelease body is of an optimized volume representing a compromise betweenthe volume that is great enough in total to offer a strong enoughstructure in an inexpensive material, such as a simple plastic forexample, optionally reinforced with glass fibers or any equivalent, anda minimized volume to allow satisfactory pivoting of the movable body,easy insertion of the base, and satisfactory forward thrusting of aboot. This concept is less expensive than prior art concepts whichrequire the use of a metal part.

In the embodiment illustrated, the carrier 1, which can be seen inparticularly in FIGS. 5-8, comprises a fixed release body 4 that takesthe form of a monolithic central portion, in a single body, extendingfrom the base 3 of the carrier near the surface of the ski to thehighest part of the carrier, and across a large width of the carriermeasured in the y direction. This fixed central body 4 comprises anessentially cylindrical upper part 5 oriented transversely relative tothe heelpiece and comprising a transverse tubular opening 6 designed totake the pivot 10 which connects it to the movable body 21. The upperpart 5 comprises at its rear end a region that departs from thecylindrical form to form a ramp 7 which performs the release function byacting on the piston 24 of the tubular body 21, as will be detailedlater. The ramp 7 extends transversely across the full width of thecentral body 4, parallel to the transverse opening 6 in the y direction,and is roughly triangular in cross section, having a vertex 8 between anupper slope 9 and a lower slope 9′. This upper part 5 is directlyconnected to the carrier base 3 by a lower part of the fixed body 4 thatextends across the full width of the upper part 5 and has a relativelynarrow region of small dimension in the longitudinal direction x. As aresult, the body 4 represents a first means of connection and supportfor the surface of the ramp 7. In the embodiment, this narrower regioncomprises a minimal dimension L of around 11 millimeters, illustrated inFIG. 5. The use of a release body 4 that is narrow in the lower partbeneath the release ramp 7 is advantageous because it saves space,facilitating the placing in movement of the movable body 21 and allowingthe definition of the release ramp that facilitates the engagement anddisengagement of the boot in the heelpiece while providing an effectiverelease function. More generally, a minimal dimension of this body inthe longitudinal direction x of between 8 and 14 millimeters isadvantageous. With such a geometry, the movable body achieves anamplitude of rotation of more than 70°. When it is in its closedposition shown in FIG. 1, it has a high position in which the axis ofsymmetry of the spring 23 is at an angle of about 65° above a horizontalplane, containing the rotary pivot 10, which allows the jaw 22 to exerta large forward thrust on the inserted ski boot to ensure release byrotation of the front stop in the event of a twisting fall by the skier.When it is in its open position shown in FIG. 2, it has a low positionin which the axis of symmetry of the spring 23 is at an angle of about8° below the horizontal plane containing the rotary pivot 10, whichallows the jaw 22 to reach an upward orientation suitable for easyinsertion of a ski boot. In the embodiment depicted, the movable bodythus has an amplitude of rotation of 73° between its two extremepositions. In a variant, a reinforcing rib (not shown) may be providedbetween the lower slope 9′ of the ramp 7 and the narrow part of thelower part of the fixed body 4.

Two lateral arms 11 are additionally attached to the carrier 1. At thetop of these are openings 12 to take the connecting pivot 10 whichextends transversely from one arm to the other through the opening 6formed in the fixed central body 4 and through openings 27 formed in twolower lateral wings 28 of the movable body 21, as can be seen in FIG. 9,which fit into the space 13 between the arms 11 and the central body 4of the carrier 1. By means of this construction, some of the releaseforces applied to the ramp 7 of the central body 4 are transmittedthrough the connecting pivot 10 to the lateral arms 11. The latter thusreinforce the whole structure and represent a second ramp 7 linking andsupporting means, allowing the heelpiece to function at very highrelease levels, greater than 12 in the unit of values defined by the ISOstandard for competition alpine bindings. These attached arms 11 may bemade of the same material as the body 4, in plastic, optionallyreinforced with fibers or metal parts. As a variant, the arms 11 may bemade entirely of metal. They are screwed at the bottom to the base 3 ofthe carrier 1. As a variant, any fixing means may be suitable, such asclips, adhesive bonding or the like. In yet another variant, the armscould be molded integrally with the carrier base and/or with the releasebody.

The way the heelpiece works can be seen particularly in FIGS. 3 and 4.In FIG. 3 the heelpiece is in the closed configuration with the piston24 pressing down on the upper slope 9 of the ramp 7 in a stableposition. If a force greater than the predefined threshold is exerted bythe boot on the jaw 22 of the heelpiece, as for example if the skierfalls forward, the piston 24 is driven back until it reaches the vertex8 of the ramp 7 before finally pivoting around onto the lower slope 9′of the ramp 7, into the second more open stable position shown in FIG.4.

The release surface on the carrier has been depicted by way of a ramp 7,which offers an advantageous release behavior. However, this surfacecould be different and in a variant could be more generally in the formof any cam surface. Moreover, this release surface could be of any sizeand thus could for example occupy less than the full width of therelease surface.

Further, this surface has moreover been illustrated as extending acrossthe full width of a central body of the carrier between two attachedarms. As a variant, the release body comprising the release surfacecould be of any other geometry, including not being a central body.However, this body has a shape that allows a direct connection betweenthe release surface positioned at its upper end to the carrier base by aconnecting means separate from the connecting pivot 10 and/or theattached arms. The release body could occupy more than half the width ofthe heelpiece to have a volume such that it can have great strength.Moreover the release body will advantageously be a one-piece componentso that it can be injection-molded or shaped in a plastic and therelease surface will occupy a large surface area in order to havesufficient strength. This body may be made of any rigid plastic, such aspolyamide, optionally reinforced by a fiber-based structure. In avariant, the release body may be an assembly of a number of separatecomponents, optionally made of different materials. For example, thisbody may comprise a top part made of plastic comprising the releasesurface, and a bottom part underneath this release surface to connect itdirectly to the carrier base, which bottom part may be made of anymaterial.

Lastly, the shape of the attached arms may also be different. Forexample, the arms may be positioned in contact with the central fixedbody and not define a space 13 as in the embodiment depicted, in whichcase the movable body would be positioned on the outside of theseattached arms. Alternatively, a single attached arm may be sufficient.In this case, this arm could be centered and could pass through anopening in the release body, for example. This arm or these arms takethe form of a component connected to the carrier base and separate fromthe release body, so as to form a reinforcement of this release bodywhile supporting some of the forces acting on the release surface andtransmitted by the pivot of the movable body. The arm or arms may be ofany shape and size to allow this function to be performed.

The concept of the invention can thus be summarized as the use of acarrier for receiving a movable body of a heelpiece in the second familyreferred to in the preamble, this carrier comprising a construction inwhich a base forms its bottom part, suitable for connection to a ski,and in which the release surface is not only directly connected by therelease body to this base, by a first connecting means, but is alsoconnected in parallel to the base by at least one reinforcing arm,through the mounting pivot of the movable body of the heelpiece, by asecond connecting means, the release surface and the reinforcing armboth being connected to the connecting pivot of the movable body of theheelpiece.

1. A ski boot safety binding heelpiece able to occupy at least twopositions, an open position and a closed position, in which latter it issuitable for the safe binding of a ski boot for skiing purposes, theheelpiece comprising a movable body (21) comprising a release spring(23) to allow release of the boot by the opening of the heelpiece in theevent of a force greater than a predetermined threshold, this body (21)occupying two different positions in each of the two positions of theheelpiece, the body (21) being movable relative to a carrier (1) about aconnecting pivot (10), and the carrier (1) comprising a carrier base (3)and a release body (4) comprising a release surface, wherein the releasesurface is connected to the carrier base (3) by a first connecting meansformed by the release body (4) and by a second connecting means formedby the connecting pivot (10) connecting the carrier (1) to the movablebody (21) and at least one reinforcing arm (11).
 2. The ski boot safetybinding heelpiece as claimed in claim 1, in which the release body (4)is also directly connected to the connecting pivot (10) connecting thecarrier (1) to the movable body (21) and in which the release surfaceacts on a piston (24) of the movable body (21).
 3. The ski boot safetybinding heelpiece as claimed in claim 2, in which at least that part ofthe release body (4) which comprises the release surface is made ofplastic or of fiber-reinforced plastic.
 4. The ski boot safety bindingheelpiece as claimed in claim 3, in which the release body (4) is aone-piece body made of plastic or fiber-reinforced plastic.
 5. The skiboot safety binding heelpiece as claimed in claim 1, in which themovable body (21) has a downwardly open region (29) between the jaw (22)of its forward end and a piston (24) acted upon by the release surfaceof the carrier (1).
 6. The ski boot safety binding heelpiece as claimedin claim 1, in which the release body (4) is a central body extendingfrom the carrier base (3) to the upper part (5) of the carrier.
 7. Theski boot safety binding heelpiece as claimed in claim 6, comprising twolateral arms (11) arranged on either side of the release body (4). 8.The ski boot safety binding heelpiece as claimed in claim 7, in whichthe lateral arms (11) define a space (13) between the release body (4)and themselves in such a way as to be able to accommodate a part (28) ofthe movable body (21).
 9. The ski boot safety binding heelpiece asclaimed in claims 6, in which the release body (4) comprises anessentially cylindrical upper part (5) oriented transversely relative tothe heelpiece, comprising a transverse tubular opening (6) designed toaccommodate the pivot (10) connecting it to the movable body (21), thisupper part (5) comprising the release surface.
 10. The ski boot safetybinding heelpiece as claimed in claim 9, in which the release body (4)comprises a lower part connecting its upper part (5) to the carrier base(3), this lower part comprising a narrow part whose dimension measuredin the longitudinal direction is between 8 and 14 millimeters.
 11. Theski boot safety binding heelpiece as claimed in claim 1, in which themovable body (21) has an amplitude of rotation of more than 70° betweenits two positions.
 12. The ski boot safety binding heelpiece as claimedin claim 1, in which the release body (4) and the arm or arms (11)comprise openings (6, 12) to accommodate the pivot (10) connecting themto the movable body (21).
 13. The ski boot safety binding heelpiece asclaimed in claim 1, in which the release surface is a ramp (7).
 14. Adevice for binding a ski boot to a ski, comprising a front binding toaccommodate the front part of a ski boot, and wherein it comprises aheelpiece as claimed in claim 1 to accommodate the rear part of the skiboot.
 15. A ski comprising a ski boot safety binding heelpiece asclaimed in claim 1.